Title :
Multipacting analysis of a quarter wave choke joint used for insertion of a demountable cathode into a SRF photoinjector
Author :
Burrill, A. ; Ben-Zvi, I. ; Cole, M. ; Rathke, J. ; Kneisel, P. ; Manus, R. ; Rimmer, R.
Author_Institution :
BNL, Upton
Abstract :
The multipacting phenomena in accelerating structures and coaxial lines are well documented and methods of mitigating or suppressing it are understood. The multipacting that occurs in a quarter wave choke joint designed to mount a cathode insertion stalk into a superconducting RF photoinjector has been analyzed via calculations and experimental measurements and the effect of introducing multipacting suppression grooves into the structure is analyzed. Several alternative choke joint designs are analyzed and suggestions made regarding future choke joint development. Furthermore, the problems encountered in cleaning the choke joint surfaces, factors important in changes to the secondary electron yield, are discussed and evaluated. This design is being implemented on the BNL 1.3 GHz photoinjector,[1] previously used for measurement of the quantum efficiency of bare Nb, to allow for the introduction of other cathode materials for study, and to verify the design functions properly prior to constructing our 703 MHz photoinjector with a similar choke joint design.
Keywords :
accelerator RF systems; accelerator cavities; cathodes; electron accelerators; electron beams; linear accelerators; particle beam injection; SRF photoinjector; cavity modification; coaxial lines; demountable cathode insertion; electron beam; energy recovery linac project; multipacting analysis; quantum efficiency; quarter wave choke joint design; superconducting RF photoinjector; Acceleration; Cathodes; Cleaning; Coaxial components; Cooling; Electrons; Inductors; Niobium; Radio frequency; Testing;
Conference_Titel :
Particle Accelerator Conference, 2007. PAC. IEEE
Conference_Location :
Albuquerque, NM
Print_ISBN :
978-1-4244-0916-7
DOI :
10.1109/PAC.2007.4441311